package p2000;

import java.text.DecimalFormat;
import java.util.Scanner;

public class Main2002计算球体积 {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while (scanner.hasNextDouble()) {
            double r = scanner.nextDouble();

            double result = 4D * 3.1415927D * r * r * r / 3D;
            System.out.println(new DecimalFormat("#.000").format(result));
            //System.out.println(String.format("%.3f", result));
        }
    }

}
